i just got a pair of jl VR componets and im going to pick up another pair of jl coaxial speakers tomorow im putting the componets in the front and the coaxial in the back. i was wondering if i should get a amp for just the front speakers and run the rear speakers off the head unit or if i should get a four channel amp and run all of the speakers to the amp. please help there in a jeep grand cheroke if wondering thanks.